Date: Fri, 6 Sep 2013 15:31:15 -0300 From: Luiz Otavio O Souza <lists.br@gmail.com> To: Sean Bruno <sbruno@freebsd.org> Cc: freebsd-embedded <freebsd-embedded@freebsd.org> Subject: Re: GPIO hint meanings Message-ID: <CAB=2f8yEx4UPc1QeHP%2BbJCDadDRvBJyvTkPjztVv4VG5uoULQw@mail.gmail.com> In-Reply-To: <1378488150.1637.5.camel@localhost> References: <1378488150.1637.5.camel@localhost>
next in thread | previous in thread | raw e-mail | index | archive | help
On 6 September 2013 14:22, Sean Bruno <sean_bruno@yahoo.com> wrote: > I think I have a fairly firm grasp on what some of the mips/gpio hints > mean, e.g.: > > hint.gpio.0.pinmask > hint.gpioled.0.at > hint.gpioled.0.name > hint.gpioled.0.pins > > Fairly straightforward. > > Now, what do these mean/do: > > hint.gpio.0.function_set > hint.gpio.0.function_clear > > ? > > Sean > > p.s. I think I'll take this and thrash together a gpioled(4) and gpio(4) > man page if I can understand better. > Hi Sean, Some of the GPIO pins on this SoC family (ar724x, ar71xx and ar9xxx) can be set between GPIO and an alternate function. So adding a pin to function_set enables this alternate function and the function_clear disables it (sometimes the bootloader doesn't initialize properly those pins). Each SoC has its own set of pins and functions. For ar71xx the pins 0 and 1 can be used as additional SPI chip select outputs, pins 9 and 10 are used for UART and there are also reserved pins for a SLIC/I2S interface. Luiz
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAB=2f8yEx4UPc1QeHP%2BbJCDadDRvBJyvTkPjztVv4VG5uoULQw>